Agriculture Reference
In-Depth Information
The problem of regeneration has always been of great interest for scientists-biolo-
gists, crop growers and livestock breeders, professionals and amateurs, and in particu-
lar horticulturists [9, 10]. All signs of post-trauma regeneration can be classifi ed into
two large groups—morphogenetic regeneration, when lost parts and organs reproduce,
and also a new organism from one part of a primary body can develop, including the
one from a separate cell
in vitro
; and nonmorphogenetic post-trauma regeneration,
which results in healing of all possible wounds [8]. The cases of so-called compensa-
tory regeneration were described, when, after removing a part of a stem or a root, a
plant reproduces a lost organ (morphogenetic regeneration), or when all the leaves but
one were removed, and this only leaf grows in size considerably and provides leafl ess
plants with photosynthesis products [11].
The results of post-trauma self-repair in plants can be explained by cambial activ-
ity [8], which, depending on phylogenetic peculiarities, is seen in basic specifi c and
varietal distinctions concerning the ability to regenerate; both potential productivity
and ecological adaptability of plants depend on it [11]. Among other factors associated
with the rate and the whole course of regenerative processes, the following should be
mentioned: ontogenetic peculiarities of an individual, its physiological condition, and
endogenous and exogenous factors of chemical, physical, and biological nature as
well. These are various chemical compounds, wound provocative, ionizing radiation,
temperature and moisture of the air and soil, photo-period, phyto-sanitary condition,
ontogenesis phase, and alike [8].
In the mid-thirties of the previous century, N.P. Krenke applied quantitative meth-
ods in studying age variation of somatic characteristics and formogenesis and regen-
eration factors, specifi c aspects of joining grafting components, and reasons for the
formation of chimeras in plants. In his works [7], which are still actual, the importance
of regeneration ability for the success of vegetative plant propagation is emphasized;
this became a good foundation for further theoretical and applied research [8, 10, 11].
N.P. Krenke classifi ed all stress factors as natural and artifi cial, normal and abnormal
(e.g. graft of a cutting in an upside-down position), with integrity breakage of some
parts or their separation from a plant, including further analysis of regeneration poten-
tial of a separated part or those parts that remained in an initial organism. The factors
of grafting plant parts (structural, physiological, combined-factorial) were described,
when translocation of some elements of a plant itself or introduction of unnatural ele-
ments to a plant took place, as well as other changes of plant details/parts affected by
natural factors, and also bending, twisting, centrifugation, and other artifi cial effects
[7]. Thermal, chemical, and radiation stresses can be of natural origin; they can result
from by-effects of technical-genetic activity of humans or conscious special impact,
etc. [8].
Plants, as well as their parts, change both quantitatively (mass, size, etc.) and
qualitatively in the process of individual development. Plants move from the fi rst (ju-
venile) phase, which lasts from seed germination to fruiting of a seedling, to an adult
plant, and then they grow old. Such ontogenetic variation can be typical for both an
individual seedling and a clone itself. Long-lived clones of grape and fruit trees keep
their inheritance in most cases; however, their current properties do not always coin-
cide with the features described by distant pomologists. Some typical physiological,
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